The invention relates to a patching arrangement for containers, pipes and similar objects, having an inflatable, flexible pad with an upper and a lower layer, and having two tensioning members, preferably in the form of straps.
Patching arrangements of this kind, which are also called patching pads, are usually rectangular in shape and have apertures for attachment along their narrowest sides, into which the tensioning members are snapped by means of spring-tensioned safety hooks.
In order to seal a leak on a container, this patching pad is placed over the place of leakage, the straps are wrapped around the container, connected to the eyes or spring safety hooks of the other narrow side and strapped tight. Thereafter, the final sealing is achieved by inflating the pad.
However, this kind of known patch is disadvantageous when the container has a small diameter, i.e., in cases where pipes of five to fifty centimeters are concerned. Furthermore, there are disadvantages if the pipe which has to be sealed has a leakage along a longer part of its circumference, i.e., if a welding joint has multiple leaks or if a pipe is torn or ripped open at an angle perpendicular to its axis.
The purpose of this invention is to avoid disadvantages of the above patch and to improve such patches so they can be attached quickly and conveniently on the leak. Furthermore, the patches should be as far as possible independent of the particular pipe diameter so that it can be applied conveniently in places of limited access.
The apparatus for patching leaks of the present invention solves this task in such a way that the lower layer is manufactured with a highly stretchable rubber elastic material and the upper layer is resistant to stretching. Also, the pad is made in a form for wrapping it around the object to be sealed. Furthermore, the pad is extended on each longitudinal side to match the width of the straps so that these extensions, also known as side straps, give a support surface for the straps.
Contrary to patches of the prior art which only partially cover the circumference of the leaking pipe and which utilize the straps to form a closed ring, the patch of the present invention is formed like a bandage and covers the leaking section of pipe in one wrapping in at least one full turn. The straps press the side strips of the patch tightly against the leaking pipe, which gives support for the sealing process along the area of the pad. Without the support of the straps placed around the side strips, the inflated pad would only touch the leaking pipe along a circumferential line, so that a planar sealing area is not achieved.
The total length of the present patching apparatus is chosen in such a way that it is approximately the same as the circumference of the largest pipe diameter it can be applied to. This patching arrangement can also be used for much smaller diameter of pipes, if it is wrapped in as many overlapping turns as necessary. Consequently, there is a very wide range of diameters of pipes which can be covered. As needed, it is therefore possible to select the needed correct patching without additional measurements.
In the range it is designed for, the invented patching apparatus covers the area from the largest to the smallest diameter of any leaking pipe without gaps in between.
In the deflated state, the patching apparatus is very thin so that it can be mounted on a pipe even in places of limited accessibility. The flexibility of the lower, and especially the upper, reinforced layer is chosen in a way that wrapping is simple even in tight turns. It is especially chosen in a way that the invented patching apparatus can also be applied in areas of pipe bends, in which a special advantage of the invention can be seen.
On the one hand, the width of the patching apparatus is so large that a sufficiently wide, typically encountered leak sealing collar is created; but on the other hand, the width is not too large to handicap implacement along pipe bends and pipe curves. A width of twenty centimeters has been proven very practical. In practical applications, it has been shown that all leaks on commonly used pipes can be sealed if patching apparatus of this width, but of different length, in particular with a length of ninety to one hundred-seventy centimeters, are available. As a consequence, this provides for the wide range of application of each single patching apparatus. Therefore, the practical useage is considerably simplified. When utilizing the pad, time-consuming selection considerations are not needed, since utilization always occurs under time pressure. Also stocking and space considerations in an emergency vehicle are less important problems.
It is especially advantageous, for practical applications of the invented patching apparatus, that the straps are either attached to the rear wrapping end of the pad or to each of the side strips. Then the whole patching arrangement consists of one piece so that the practical utilization is very much simplified, since important parts cannot be lost or do not have to be looked for.
Under the invention, straps are nearly completely obsolete, particularly if the side strips of the patch take over the task of the straps. Then, for example, a hook is attached on each side of the strips near the rear wrapping end of the pad. Independent of the pipe diameter, this hook can be connected to one of several eyes arranged along the upper side of the side strips. These eyes are separated a certain distance from each other. Instead of a hook-eye connection, a hook based on a friction principle can be chosen.
The valve of the pneumatic pad is best placed on one side of one of the side strips or around the center of the narrow side at the wrapping end. When the pad is wrapped up in the radial direction, it does not disturb or handicap the wrapping procedure and it is still easy accessible.
The lower layer of the pad is manufactured according to the invention from synthetic rubber which has high flexibility. To prevent the lower pad layer from dropping into the interior of a broken pipe, in particular in cases of large and sharp-edged holes, it is proposed to support the bottom layer of the pad with an external, reinforced layer. This reinforced layer can be arranged in such a way that there is an U-shaped area of no reinforcement, but high elasticity between the reinforced layer, both sides of the side strips, and the one cross strip in the rear at the wrapping end. With such a patching apparatus, it is also possible to seal pipes broken all way around; and two pipes can be temporarily butt-joined tightly, i.e., for testing purposes.
The narrow side where wrapping starts is preferably edged like a wedge, which eases the wrapping and avoids step build-up between the first and second wrapping layers. Furthermore, an acute-angled side provides the user with the best indication of where wrapping of the patching apparatus should start.
Preferably, the side strips have a projecting ridge on the outer edge, which limits sliding of the straps. As an alternative, the contact surface between the side strips and the straps can be corrugated or nonskid formed in such a way that a lateral movement of the straps is hindered.
The complete patching apparatus, i.e., the pad and the surrounding framelike side and cross strips, is manufactured by the proper connection of the upper and lower layer. To prevent a breaking or ripping of both layers, it is advantageous to plan for a reinforcement covering the area of connection between the layers in a similar manner known for pneumatic elevating pads.
Further features of the invention can be deduced from the claims and the following description.